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(Coleoptera, Diptera, Hymenoptera and Lepidoptera)
by
Brian Pitkin, Willem Ellis, Colin Plant and Rob Edmunds
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ASTRAGALUS.
Milk-vetches and Wild Liquorice. [Fabaceae]
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Seven
species of Astragalus are recorded in Britain. These include
the native Alpine Milk-vetch (A. alpinus), Purple Milk-vetch
(A. danicus) and Wild Liquorice (A. glycyphyllos).
Eight British miners are recorded on Astragalus.
A key to the European miners recorded on
Astragalus is provided in Bladmineerders van Europa.
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Key for the identification of the known mines of British
Diptera recorded on Astragalus
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Note: Diptera larvae may live in a corridor mine, a corridor-blotch mine, or a blotch mine, but never in a case, a rolled or folded leaf, a tentiform mine or sandwiched between two more or less circular leaf sections in later instars. Pupation never in a cocoon. All mining Diptera larvae are leg-less maggots without a head capsule (see examples). They never have thoracic or abdominal legs. They do not have chewing mouthparts, although they do have a characteristic cephalo-pharyngeal skeleton (see examples), usually visible internally through the body wall. The larvae lie on their sides within the mine and use their pick-like mouthparts to feed on plant tissue. In some corridor miners frass may lie in two rows on alternate sides of the mine. In order to vacate the mine the fully grown larva cuts an exit slit, which is usually semi-circular (see Liriomyza huidobrensis video). The pupa is formed within the hardened last larval skin or puparium and as a result sheaths enclosing head appendages, wings and legs are not visible externally (see examples).
See Key to non-Diptera.
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1a > Stem-miner: Details
unknown. |
On Astragalus in British and elsewhere. Essex (Bland,
2001). Czech Republic, French mainland, Germany, Lithuania,
Slovakia, Sweden (Martinez in Fauna Europaea).
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Melanagromyza
astragali Spencer, 1976 [Diptera:
Agromyzidae].
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1b > Leaf-miner: A distinctive mine primarily above mid-rib, with irregular short
lateral offshoots into leaf blade. Pupation external (Spencer, 1972:
51 (fig. 172), 55; Spencer, 1976:
270, 271 (fig. 486)).
Branched,
whitish, upper-surface corridor; main axis overlying the midrib;
side branches overlying the main lateral veins. (In Campanula and Phyteuma the mine is much less branched, sometimes nothing
more than a corridor on top of the midrib). Frass in rather long
strings. Usually the mines begins as a long and narrow, shallow,
tortuous lower-surface corridor that ends upon the midrib but otherwise
is not associated with the leaf venation. Often this initial corridor
is filled with callus, and then even less conspicuous. Pupation
outside the mine.
A
linear mine on the upper surface, usually following the midrib and
showing side branches along the veins. The frass is in strings. |
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Polyphagous. On more than 40 host genera in 15 families, but not yet on Astragalus, in Britain,. Widespread
throughout Britain. Also recorded in the Republic of Ireland.
Widespread in continental Europe.
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Liriomyza strigata (Meigen, 1830) [Diptera: Agromyzidae].
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1c > Leaf-miner: Corridor leaf-mine in leaves. An upper surface linear mine
with frass in conspicuous greenish strips, largely alternating at
each side of the channel (Spencer,
1976: 241).
Upper-surface,
unbranched corridor, relatively broad from the start on, but only
weakly widening subsequently. The fresh mine is bright green, but
turns whitish, later brown, quickly. Frass in a wide green band
in the centre of the corridor, with small black granules at either
side. Pupation outside the mine.
Forms
an upper surface mine, with the frass in a green strips. |
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Liriomyza congesta puparium
Image: © Willem Ellis (Bladmineerders van Europa) |
Polyphagous. On numerous genera of Fabaceae in Britain and elsewhere, including Astragalus, in Britain
and elsewhere. Widespread
in Britain. Also recorded in the Republic of Ireland and widespread
and common throughout most of Europe
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Liriomyza
congesta (Becker, 1903) [Diptera: Agromyzidae].
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1d > Leaf-miner: A short, irregular, linear upper surface mine on any part of the
leaf. Also recorded from young pods (Bland, 1997a).
Long
corridor mine. As a rule the first part of the mine is lower-surface,
the later part upper-surface. Often the loops are so dense that
a secondary blotch is the result. Because upper- and lower-surface
corridor segments often cross, the mine obtains a strange array
of transparant patches. There is no association with the midrib.
Frass in strings and thread fragments. Pupation outside the mine;
exit slit in upper epidermis.
Mine not associated with the veins or midrib of the leaf (It is this character which enables distinction from another Agromyzid pest species - Liriomyza huidobriensis). The larvae may leave one leaf (if not large enough) and enter another leaf, via the petiole). It exits the leaf to pupate through a semi-circular slit in the upper surface of the leaf. |
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Polyphagous. On 119 plant genera in 31 plant families of which only 4 plant genera in 2 plant families, but not yet on Astragalus, in Britain. On Astragalus elsewhere. Local, probably introduced
to Britain. Widespread in continental Europe particularly in Botanical
Gardens and glasshouses. Also recorded in Egypt.
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Liriomyza bryoniae (Kaltenbach, 1858) [Diptera: Agromyzidae].
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1e > Leaf-miner: A
narrow linear mine adjoining the leaf margin in the first instar,
which later develops into an irregular blotch with conspicuous lumps
of greenish frass (Spencer, 1976:
302).
The
first instar larva makes a narrow upper-surface corridor along the
leaf margin. After it has moulted it begins a large upper-surface
blotch. Frass in conspicuous green lumps, that can run out irregularly.
Pupation outside the mine.
Forms
a narrow linear mine by the margin of the leaf which later develops
into a blotch. The blotch has clumps of greenish frass. |
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On Astragalus and Colutea in Britain and Anthyllis, Astragalus, Cicer, Colutea, Coronilla, Cytisus, Lathyrus, Oxytropis,
Securinega and Vicia elsewhere. Widespread in continental Europe.
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Phytoliriomyza
variegata (Meigen, 1830) [Diptera: Agromyzidae].
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Key for the identification of the known mines of British
non-Diptera recorded on Astragalus
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Note:
The larvae of mining Coleoptera, Hymenoptera and Lepidoptera may live in a corridor mine, a corridor-blotch mine, a blotch mine, a case, a rolled or folded leaf, a tentiform mine or sandwiched between two more or less circular leaf sections in later instars. Larva may pupate in a silk cocoon. The larva may have six legs (although they may be reduced or absent), a head capsule and chewing mouthparts with opposable mandibles (see video of a gracillarid larva feeding). Larvae of Hymenoptera and Lepidoptera usually also have abdominal legs (see examples). Frass, if present, never in two rows. Unless feeding externally from within a case the larva usually vacates the mine by chewing an exit hole. Pupa with visible head appendages, wings and legs which lie in sheaths (see examples).
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1a > Leaf-miner and case-bearer: The larva lives outside the mine, protected by a case, and feeds on the underlying plant tissues via a hole cut in the epidermis. From that point it eats away as much leaf tissue as it can reach without fully entering the mine. Mine does not contain frass (Coleophora species) |
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1b > Leaf-miner, but not a case-bearer: The larva lives mainly inside the mine. Mine usually contains frass. In later instars the larva may live sandwiched between two more or less circular sections cut from the leaf. |
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2a >
Leaf-miner and case-bearer: The initial mine is like that of a nepticulid.
The case is made form excised leaf portions, which are added to
the oral end, leading to the ringed appearance. The larva causes
the leaf to have white blotches. Identification cannot be made on
these alone as similar blotches can be made by early instar larvae
of the Common Blue butterfly (Polyommatus icarus).
Oviposition
at the leaf underside, mostly in a vein axil. The larva begins by
making a narrow winding corridor with much frass in a broad central
line. The corridor reminds that of a nepticulid (but the egg has
a finely reticulate surface, unlike the smooth nepticulid egg.)
In the end the corridor widens into an oval blotch, usually close
to the leaf margin, out of which the first case is made. The full
grown larva in a greyish brown composite leaf case of about 6 mm,
attached to the underside of a leaf. The oldest quarter of the case
is bivalved, laterally compressed, and is at an angle of 70°
with the anterior part of the case. The mouth angle is around 40°. |
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On Lotus, but not yet on Astragalus, in Britain,
and ? Astragalus, ? Dorycnium, Lotus, ? Medicago and ? Oxytropis elsewhere. Widespread in Britain, Ireland
and continental Europe.
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Coleophora
discordella Zeller, 1849 [Lepidoptera: Coleophoridae]. |
3a > Leaf-miner: In the first instar the larva mines the leaves, forming short,
irregular, blotch-like mines, but in later instars it lives externally,
feeding in spun leaves and often twisting those of tender shoots. Larval head light-brown or yellowish brown, edged with black postero-laterally,
ocellar area blackish; prothoracic plate black edged with whitish
anteriorly; abdomen dull dark green; pinacula distinct, black,
sometimes brownish but with black bases to setae; anal plate large,
black (Bradley et al., 1973).
Small,
full depth mine without a definite shape; little frass. Some silk
is deposited in the mine. The larva soon leaves the mine and continues
feeding among spun leaves. |
Polyphagous. On numerous genera and species of plant families, but not yet
on Astragalus, in Britain. On numerous genera
and species of plant families including Astragalus elsewhere.
Widespread in Britain and continental Europe. Also recorded from
the Channel Is.
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Cnephasia
incertana (Treitschke, 1835) [Lepidoptera: Tortricidae]. |
3b > Leaf-miner: An irregular gallery filled with greenish frass,
leading to a circular or oval blotch with blackish frass arranged
in a spiral fashion. The very first part of the mine is a densely
contorted corridor of about 2 mm long, that quickly turns brown.
It is followed by a more or less straight corridor of c. 10 mm,
entirely filled with greyish green frass. This suddenly widens into
a round blotch that during its expansion overruns the earlier corridor
and in the end may occupy half of a Laburnum leaflet. The
frass, greenish at first, black later, is deposited in the bloth
in roughly concentric arcs, glued to the upper epidermis. Pupation
external, exit slit in upper epidermis |
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On Cytsisus, Genista, Laburnum, Lupinus and Piptanthus, but not yet on Astragalus, in Britain and Astragalus, Chamaecytisus, Genista, Laburnum, Laburnocytisus,
Lupinus and Petteria elsewhere. Widespread in Britain
and continental Euorpe. Also recorded in the Republic of Ireland.
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Leucoptera
laburnella (Stainton, 1851) [Lepidoptera:
Lyonetiidae]. |
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